Vehicle cab

ABSTRACT

A cab for a vehicle, such as an all terrain vehicle, a tractor, or small construction vehicle, is constructed of twin-sheet plastic panels that can be easily assembled, preferably with snap-together interlocking features. One of the panels can be a door panel having a door hinged to a door frame to control passage through a doorway. Both the door and the door frame have spaced apart hinge knuckles that interleave along a hinge axis to allow the door to pivot about a hinge pin. The door and door frame can be molded in a single twin-sheet panel. The two walls of the panel are fused together along the outer periphery of the panel door portion and the inner periphery of the panel door frame portion. The door is separated from the door frame by cutting the each of the walls along a door perimeter between the door and door frame portions of the molded panel. Preferably, the walls are not fused along the non-hinge sides of the door perimeter so that the walls can be cut in a manner to provide an overlap at the door/door frame interface.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of allowed U.S. patent application Ser.No. 10/971,397, filed Oct. 22, 2004 and issued as U.S. Pat. No.7,216,926 on May 15, 2007, which claims priority to U.S. ProvisionalApplication No. 60/513,267, filed Oct. 22, 2003.

STATEMENT OF FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

FIELD OF THE INVENTION

This invention relates to vehicle cabs, and in particular to a cab for asmall vehicle like an all terrain vehicle (ATV), a lawn or gardentractor, or small construction equipment.

BACKGROUND OF THE INVENTION

There are many motorized vehicles used for utility or recreation thathave no cab such that the rider and any passengers are exposed to theopen air and thus subjected to environmental conditions and inclementweather, which are made worse by wind effects from the speed of travel.Lawn maintenance vehicles provide one example of such vehicles. Anothertypically cab-less motorized vehicle is an ATV. There are approximately800,000 ATV's sold annually, about half of which are in the utilityclass, and perhaps 10 or so million of all styles of ATV's in useworldwide. The utility ATV's are used by sportsmen, for hunting andfishing, farmers, ranchers and in the construction and utilityindustries. Snow removal using an ATV is growing in popularity.

A cab would be a desired addition to such vehicles for many of theseapplications. The cab would provide protection to the rider from theelements. The cab would allow the rider to sit on the vehicle in asheltered environment, while performing activities, such as ice fishing,with the vehicle running or off. At the same time the cab should provideventilation and good visibility.

One concern is to make the cab rugged and durable so that it canwithstand impact, from tree branches or rocks common in trail andoff-road riding, without being two heavy. Another, concern is to makethe cab easy to assemble (if necessary) and to make it easy to installand remove from the vehicle, which is another reason favoring the use oflightweight materials.

Large industrial or commercial equipment, such as some farm orconstruction vehicles, often have cabs, which are sealed and heated orcooled while the vehicle is operated. However, the cabs in such largevehicles are usually permanently attached to the vehicles, andregardless, they are typically made of heavy duty construction.

Golf carts and the like sometimes have some type of structure designedto protect the riders from the elements. For example, it is common forgolf carts to have a plastic or fiberglass roof mounted over the seatingarea by four metal posts. A transparent panel can be mounted to thefront two posts to provide a windshield, however, typically the rear andsides of the cart are open to the elements. Thus, while providinglightweight and perhaps dismountable structures, they are not wellsuited for the higher speeds of ATVs nor do they provide an enclosedinterior for the rider(s).

SUMMARY OF THE INVENTION

The present invention provides a cab for motorized vehicles made oflightweight, but durable plastic panels having a double wallconstruction. The two walls are primarily spaced apart to give the cab ahollow and thus increased wall thickness providing good structuralrigidity and a robust appearance. At certain locations the walls arebrought in close relation, and sometimes fused together, to defineclosed edges or certain structural or working features of the cab.

In one aspect the present invention provides a plastic resin vehicle cabwith a roof panel and an upright panel. One of the first and secondwalls of the roof panel defines an integral connection part that ismateable with an integral connection part defined by one of the walls ofthe upright panel to connect the roof panel to the upright panel withoutseparate fasteners.

The cab can include several upright panels, which preferably include afront panel, a rear panel and side panels. Each of the front, rear andside panels can have an integral connection part at an upper side toconnect to the roof and at each lateral side to connect the side panelsto the front panel at the front of the cab and to the rear panel at therear of the cab.

Each pair of mating connection parts can include a snap-together featurefor positively locking the roof to the upright panels and the uprightpanels to themselves in a snap fit. In one preferred from, the matingconnection parts are tongue and groove features and the snap-togetherfeatures are boss and recess features. The roof panel can be formed withone or more grooves or pockets along its periphery and the front, rear,and side panels each define a tongue or tab extending up from a top edgeto fit into the pocket(s). And, each of the front, rear and side panelscan have one or more groove or tongue features at each lateral side thatcomplement the mating connection parts of the adjacent panel and allowthem to fit together. Preferably, each pocket is formed with a reliefchannel for accommodating a tip of the associated tongue, which can varyin sized due to slight inconsistency in the molding and/or trimmingoperations of the manufacturing process.

One of the upright panels can be a door panel having a door hinged to adoor frame or jamb. Spaced apart and offset hinge knuckles at hingesides of the door and door frame are interleaved and aligned inalternating fashion along a hinge axis along which a hinge pin extendsto pivotally mount the door.

In thus another aspect of the invention, the door and door frame arepreferably formed from a single molded panel. The door can then be cutfrom the panel and hinged to the door panel. The door is preferablylocated inside the door frame such that a doorway (bounded by the doorframe) is formed after the door is cut out.

At least a portion of the first and second walls of both the door andthe door frame portions of the panel are fused together adjacent to adoor perimeter, which is located between the door and the frame portionsof the panel. Preferably, the first and second walls are fused togetheralong the entire peripheries of the door and door frame portions of thepanel adjacent to the door perimeter to define closed edges at theperipheries of each component.

Also, the first and second walls are preferably spaced apart along atleast a portion of the door perimeter. For example, the walls can beseparated along a free side of the door opposite its hinge side. Then,when the door is cut from the panel one of the walls is cut along thefree side of the door further from the hinge side of the door than theother wall so that an overlap is created at the free side when the dooris re-assembled to the duo-frame. Preferably, the wall corresponding tothe inner side of the panel (at the cab interior) is inside of the outerside wall to act as a stop or door jamb preventing the door fromswinging into the cab interior. Such an overlapping configuration can beprovided along all non-hinge sides of the door.

The panels of the cab can be molded to fit particular vehicle models.Or, the panels can be of one or more standard sizes for universal cabsthat fit multiple sizes and types of vehicles. In the latter case,preferably the upright panels of the cab mount one or more vehiclecontour panels that essentially conform to the shape of the vehicle. Inone preferred form, the contour panels slip into slots cut into ormolded at the bottom edges of the upright panels so that an end of thecontour panel(s) fit between the walls of the associated panel(s). Stillmore preferably, the vehicle contour panel(s) are formed and cut fromthe molded panel(s) in areas of the panels which would otherwise bewaste.

Transparent or translucent materials can also be mounted to one or moreof the cab panels. For example, a transparent acrylic panel can bemounted to the front panel to provide a windshield. Or, a translucent ortransparent panel can be mounted to the door as a window or to the roofas a sunroof. The panels can fit between the walls of the panels throughslots cut into the edge surfaces at the inner periphery of theassociated opening. Sealant and/or cushioning material can be applied atthis area to seal the window and prevent rattling. The panels can befree floating or secured by adhesive or fasteners. Also, one or morepivotally mounted window panels can be provided to allow forventilation.

Additional ventilation can be achieved by holding the door ajar from thedoor frame using a multi-stage door latch, which also serves to securethe door closed. For example, a rotatable cam member with aspiral-grooved outer periphery can be used to engage a latch member onthe door frame so that as the cam member is rotated the door is heldmore or less open.

Another aspect of the invention provides a plastic resin vehicle cab,with a roof panel and a front panel. The roof and front panels have twowalls fused together at some locations and separated at other locations.The front panel defines a windshield opening and a channel or slotextending along the windshield opening. The channel opens to thewindshield opening and space between the walls so that peripheral edgesof a transparent panel can be captured between the walls.

Another aspect of the invention provides a method of making a plasticdoor panel for a vehicle cab, as well as a method of making a cab havingone or more such door panels. The method includes thermoforming twosheets of plastic resin into a two wall panel that defines a door, adoor frame and a door perimeter between the door and the door frame. Thewalls of the door and door frame are fused together adjacent to the doorperimeter for at least a portion of the door perimeter. At leastportions of the walls are removed, for example by a cutting operation,along the door perimeter to separate the door from the panel and definea doorway of the door frame. The door is then assembled to the doorframe at the doorway. Preferably, hinge knuckles of the door and doorframe interleave and hingedly join together with one or more hinge pins.In addition, one or more vehicle contour panels can be mounted to abottom edge of the door panel, preferably by inserting them into a slotin the door panel and secured by fasteners. Further, a window opening iscut into the door (or door frame) so that a translucent or transparentpanel or sheet can be mounted at the opening, preferably by fitting theedges through a slot and between the walls of the door (or door frame).

Thus, the inventor has determined that twin-sheet vacuum thermoformingor blow molding of plastic resin is ideal material and manufacturingprocess for making a vehicle cab. The plastic material is rugged and canbe pre-colored or painted. The twin-sheet vacuum thermoforming are blowmolding processes producing a part that provides the required featureson both the interior and exterior of the product without additionalwelding, bonding or assembly of separate pieces to the panels. Theseprocesses provide the ability to create plastic panels that can beeasily removed or replaced that allow the cab to be easily installed andremoved from the vehicle. The cab can be lightweight and yet be veryheavy duty given its two wall construction.

The cab can be a monolithic structure, or preferably, a multi-pieceassembly. The multi-piece assembly is preferable in many applications asit will pack flat for shipping and storage by both the manufacturer anddistributor and the end user. In addition, many more features can beprovided in a multi-piece construction because there will not be therestrictive draft angles required for molding a single piece unit. Also,the styling of the finished product is much more flexible in amulti-piece construction, allowing for a much more eye appealing design.

With the multi-piece construction, the components of the cab can be usedin their entirety or partially in the following combinations: 1) thefront windshield and roof only, using a tubular support on the rear ofthe roof; 2) the front panel and windshield, roof and rear panel(without door panels); 3) the front panel and windshield, roof, rearpanel and door frames (without doors); 4) the front panel & windshield,roof, rear panel, doorframes and doors. Additionally the windows can bemade removable from the doors.

The foregoing and other objects and advantages of the invention willappear in the detailed description which follows. In the description,reference is made to the accompanying drawings which illustrate one ormore preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of an ATV fitted with a cab according to thepresent invention;

FIG. 2 is a front plan view thereof;

FIG. 3 is a view showing a twin-sheet thermoformed plastic panel doorpanel of the cab, including a door and a door frame molded integrally inthe panel, before a cutting operation along the door perimeter (shownstippled) to separate the door from the door frame;

FIG. 4 is a side view of the cab shown with its constituent panelsexploded, the door panel is shown without a window;

FIG. 5 is a side view showing an assembled door panel with the doorhinged to the door frame and the frame connected to the front and rearpanels;

FIG. 6 is a broken sectional view taken along line 6-6 of FIG. 3 showingthe molded door and door frame prior to the door being cut out;

FIG. 7 is a partial broken sectional view of a door panel with amulti-stage latch handle installed on the door taken along line 7-7 ofFIG. 5;

FIG. 8 is a partial cut-away sectional view taken along line 8-8 of FIG.5 showing the connection of the door panels to the roof panel;

FIG. 9 is an enlarged partial sectional view taken along arc 9-9 of FIG.8 showing one of the integral snap-locked, tongue and grooveconnections;

FIG. 10 is a partial enlarged view taken along arc 10-10 of FIG. 5,showing a portion of the door panel hinge;

FIG. 11 is a partial rear plan view take from line 11-11 of FIG. 7showing a multi-stage door latch;

FIG. 12 is side view of a door panel showing a pivotal window;

FIG. 13 is a partial side view of an alternate embodiment of theinvention in which the cab includes universally sized panels and vehiclespecific contour panels mounted to one or more cab panels to cover spacebetween the cab panels and the vehicle body; and

FIG. 14 is partial sectional view taken along line 14-14 of FIG. 13.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As mentioned, the present invention provides an enclosure or cab for avehicle, such as small motorized tractors, ATVs, golf carts, smallconstruction vehicles, and the like. The cab is made of double walledplastic construction. An HDPE resin is one preferred plastic andtwin-sheet vacuum thermoforming or blow molding techniques can be usedto mold the resin. The plastic double wall construction makes the cabstrong, durable and impact resistant as well as lightweight and easilyto install and remove from the vehicle. The double wall constructionalso has the benefit of allowing multiple features of the cab to bemolded at the same time, together in the same panel. For example, thedoor and door frame of a panel can be formed in one twin-sheet moldedpanel and then cut apart from each for assembly. This reduces waste ofthe material and also saves labor, for example in that the cuttingoperation to remove the door from the panel also defines the doorwaywithin the door frame. The double wall construction has the furtheradvantage of allowing the wall at the interior of the cab to have adifferent configuration than the exterior wall. Thus, each wall can bemolded to define surfaces or specific interior and exterior featureswithout effecting the other wall. Additionally, the cab can be agenerally monolithic structure including a roof and one or more uprightpanels molded integrally with each other, or more preferably, it can becomprised of separate panels making up the roof, front, rear, and sidesof the cab. In the latter case, the panels can be self-connecting suchthat separate fasteners are not required to assemble the cab.

FIGS. 1 and 2 of the drawings illustrate one preferred version of thecab 10 of the present invention installed on an ATV. This version of thecab 10 is an assembly of roof 12, front 14, rear 16 and side door 18 and20 panels. Each of these panels will be described in detail below, butgenerally the front panel includes a see-through windshield 22 andangled side windows 24, the door panels are identical (but mirrorimages) with a door 26 hinged to a door frame 28 and the rear panelincludes a rear window (not shown).

As mentioned, each of these panels is of double walled plasticconstruction, with the two walls of each panel being primarily spacedapart or separated from one another throughout the panels and fusedtogether at other locations, such as edges or to form specific features.Each of the panels is molded to include one or more integral connectionparts that engage a complementary part of one or more adjacent panels,preferably effecting a positive interlock between the panels such thatseparate fasteners and tools are not required to assemble the panelstogether. In one form, these connection parts provide tongue and groovesnap-locking interconnection, as described below.

With reference to FIGS. 1, 2, 7, 8 and 9 the roof panel 12 is generallyflat, but slightly bowed and has long spaced apart channels 30 formed inthe outer wall with vertical portions that add strength. A gutter 32 isformed around the outer periphery. The inner wall is molded with pockets34, which are spaced along all four sides of the roof panel at themargin to the inside of the gutter. Note that a single, four-sidedgroove could be formed as well. These pockets 34 form a recess includinga relief channel 36 and two opposing inwardly dished areas 38. Each ofthese pockets 34 receives an associated one of several tabs 40 moldedintegrally in spaced apart relation to project up from the upper edgesof each of the upright panels. Each tab has one or more bulges or bosses42 located and sized to fit into the dished areas 38 of the pockets whenthe panels are assembled. The bosses are easy to manufacture becausethey are molded in the line of draw of the mold. The bosses 42 extendoutward farther than the width of the pockets so that when the tabs areinserted into the pockets the walls of the pockets or the tabs willdeflect slightly until the bosses come to rest inside the dished areas.The narrow walls of the pockets resist separation of the tab and therebycreate a snap-lock type connection that positively interlocks thepanels. With this arrangement, no tools or separate fasteners areneedled to unite the panels. Further, the relief channel 36 in eachpocket can accommodate the flange at the tip of the associated tab,which may be molded or trimmed to varying lengths due to the variationsin these processes.

Each of the panels has similar integrally molded mating connectionparts. As shown in FIGS. 4 and 7, the tabs formed with the uprightpanels are located not just along the top edge but also at or alongopposite lateral sides, which allow each upright panel not only to besnapped to the roof but also to the adjacent upright panel, that is thetwo side door panels interconnect with the front panel at the front ofthe cab and the rear panel at the rear of the cab. In the preferredversion of the cab shown in the drawings, the door panels include tabsprojecting out from the lateral edges of the panels that mate withassociated pockets formed in the inner walls and at the margins of thefront and rear panels. Thus, the tabs project out from the panel edges,straight or angled as needed, to fit into the pockets formed in thefront and rear panel (inner wall) faces. Additionally, two optionalfloor boards 44 can be connected using a similar connection arrangementat the bottom of the door panels.

Thus, the lightweight plastic panels can be readily assembled togetherto construct the cab. Once assembled, the cab can be easily lifted ontothe vehicle. Any suitable method of mounting the cab to the vehicle canbe employed, such as bolting the cab to brackets (not shown) mounted tothe vehicle frame. Preferably, each upright panel is securely fastenedto the vehicle frame at the front, rear and lateral sides of thevehicle.

The cab shown in FIGS. 1 and 2 is designed so that the bottoms of thepanels conform to the contours of the vehicle, particularly the bodycomponents such as the front and rear fenders. Another, perhapspreferable, manner to fit the cab to a given vehicle is form the uprightpanels, particularly at the bottom sides, in one or more standard sizesand shapes. Then, one or more vehicle specific contour panels (such asitem 46 in FIGS. 13 and 14) can be mounted to the upright panels. In onepreferred form, a slot 48 is cut into the bottom edges of the uprightpanels so that the contour panels can be inserted between the two wallsand secured in place by an adhesive or other mechanical fasteners. Thecontour panel preferably has a bulged section 49 and the slot 48 ispreferably not over-sized so that the panels would fit snugly in place.However, sealant and/or cushioning material could be used to reducerelative movement, vibration and rattling. Even more preferably, suchcontour panels could be molded together with one or more of the cabpanels so that additional manufacturing processes are not required.Still further, these contour panels could be molded in locations thatwould otherwise be waste material, such as in an area were a windowopening would be cut out. As an alternative, the contour panels could beseparately molded using a semi-flexible polymer material that wouldconform to the varying contours of the vehicle. The area between thefenders where the operator's feet go may not need a contour panel giventhe floor boards, and even without them, this area may not need to besealed tightly since air leakage there is not particularly detrimental,particularly given that there are many open areas surrounding theengine.

As mentioned above and shown in FIGS. 5, 7 and 10, the door panels eachinclude a door frame to which is pivotally mounted a door over a doorway50. The door and door frame each have respective hinge knuckles 52 and54 at hinge sides thereof that are spaced apart and offset in oppositionto the other so that the knuckles can be interleaved in aligned along ahinge axis 56 of a long hinge pin 58 that joins the door to the doorframe. As shown in FIG. 7, the door preferably overlaps the door frame(at the doorway) along at least the free side of the door opposite thehinge, and preferably along all non-hinge sides. This reduces air gapsaround the door and also provides a positive stop that prevents the doorfrom swinging to the interior of the cab. A gap filler strip 60 can bemounted to the hinge side of the door or the door frame to cover the airgap between the hinge knuckles. Preferably, this strip is taken from awaste area of the molded panels, however, it may be a separate gasket orseal member.

According to one preferred technique, FIG. 4 of the drawings shows oneof the door panels in its post-molded and pre-cut state in which thedoor and door frame, including the hinge knuckles, are formed from thesame twin-sheet panel and not yet cut apart. The door and door frameportions of the molded panel are separated by a door perimeter 62, whichessentially outlines the door, thereby defining the outer periphery ofthe door and the inner periphery of the door frame. Notably, the door isformed inside the door frame in what becomes the doorway. Thus, in theprocess of cutting out the door, the doorway is simultaneously formed,thereby reducing both wasted and manufacturing efforts. As best seen inFIGS. 6 and 7, the two walls of the molded panel are fused together atboth sides of the door perimeter, in this case, along the entireperiphery of the door and door frame so that each part has a closed edgewhen separated. And, preferably the two walls are separated (not fusedtogether) along at least a portion of the door perimeter. Ideally, thedoor perimeter has non-fused walls along all non-hinge sides of the doorso that an overlap is created along these sides, as will be described.However, an overlap on the free side of the door (opposite the hinge)only would be sufficient. Note also that the two walls could be fusedalong the entire door perimeter, however, then there would be nointegral overlapping surfaces between the door and door frame. In thiscase a separate seal and/or door stop could be added.

FIG. 6 shows one exemplary configuration of the door perimeter in whichtwo bumps outs 70 and 72 are formed, one in each wall and extending inopposite directions, along the non-hinge sides of the door, with thebump out 70 on the inner wall being inside bump out 72. The door is cutfrom the door panel using any suitable technique such as hot knife orrouting. Each bump out can be cut for example along the cut lines markedin FIG. 6 or they can be routed off completely, taking care not to cutthrough both walls simultaneously. The cutting operation is performedalong the hinge side as well, however, here the walls are fused togetherso that both walls are cut simultaneously. After the cutting operation,the door can be separated from the door frame, with the resultingopening being the doorway. Additional trimming or edge finishing may bedesired to make clean edges on both parts. While not shown, other ribsor bumps can be molded along the door perimeter (and in the door anddoor frame) to add strength.

With the door separated, holes are drilled into the hinge knuckles ofboth parts and the door is hinged to the door frame by interleaving thehinge knuckles and sliding the hinge through the holes through anotherhole at the top or bottom of the door frame. The hinge pin can be a longpolyethylene rod or tube, and a spacer (not shown) may be used on thehinge pin between the knuckles to align the door. Since material wasremoved from the hinge side of the door perimeter, the door will shiftslightly (from its molded position) toward the hinge side after beingmounted to the door frame. The described above overlap accommodates thisso that there are no air gaps around the door. Moreover, the fillerstrip covers the gaps at the hinge side.

As shown in FIGS. 7 and 11, the door is held closed against the doorframe by a multi-stage latch 86 mounted on a pin passing through thedoor and having handles at each side. The latch is a tapered cam memberwith a peripheral groove that engages a fixed catch 88 mounted to thedoor frame. When the latch is rotated fully in one direction the camwill clear the catch so that the door can be opened. The special latchalso allows the door to be held in various ajar positions to ventilatethe cab, which may be necessary given that the operator is sharing spacein the cab with the hot engine. The taper on the cam allows the latch tochange the space between the door and the door frame as it is rotated.

All of the panels can have some type of see-through and/or ventablepanel. As already mentioned, the front panel can have the windshield 22and angled side windows 24 and the rear panel has a rear window (notshown). The roof can have a translucent panel (not shown) to provide asun-roof and the doors can have windows 90. Extruded acrylic sheets canbe used for the window panels, particularly given that material's lightweight, durability and ease to fabricate, however, it is somewhatsusceptible to being scratched. A thicker glazing or safety glass ispreferable for the windshield. Preferably, the edges of the panels forthe windshield and other windows are slipped in between the walls of thecab panels through slots located in the inner edges of cut out windowopenings. The slots can be cut higher at the upper side of the openingsto facilitate installation, and preferably the materials will allow fordistortion to fit side to side. To keep the windows from vibrating andsnug a cushioning material may be placed inside the slots. Window restsand stops can also be molded into the cab panels to constrain thewindows laterally and vertically.

As shown in FIG. 12, the door panel windows preferably have a movablewindow pane to provide ventilation. In the form shown in the drawings,this is accomplished by splitting the window into two components, a rearpart 100 would be mounted and fixed, as described above, and the frontpart 102 would pivot on a pin and rotate rearward over the inside of therear part. The door is molded to allow for clearance of the componentsand a radius on the top of the side window is designed to allow for thepivoting action. There will be an area on the front/top panel that awiper mechanism can be mounted to.

As an alternative, the side (or any) windows could be zippered in placewith a double-ended zipper. This would facilitate ventilation byallowing the front or rear portion of the window to be open.Additionally the entire window could be removed in the field, and if aflexible material is used, rolled up and placed in a pocket that wasmolded into one of the panels to receive it.

A vehicle cab that is made by either a twin sheet vacuum thermoformingprocess or a blow molding process has been described in considerabledetail. The features described enable a hollow walled plastic moldedconstruction that is uniquely adapted to provide a vehicle cab for anATV, small tractor and construction related equipment applications. Manymodifications and variations to the preferred embodiments described willbe apparent to a person of ordinary skill in the art. Therefore, theinvention should not be limited to the embodiment described.

1. A plastic door panel for a vehicle cab, the door panel comprising afirst wall and a second wall fused together in some locations andseparated from each other in other locations, wherein the first andsecond walls define a door, a door frame and a door perimeter betweenthe door and the door frame, wherein the door has a hinge side defininga plurality of spaced apart hinge knuckles and wherein the door framehas a hinge side defining a plurality of spaced apart hinge knucklesarranged offset from and in opposition to the hinge knuckles of thedoor, wherein the door can be removed from the door panel by removing atleast portions of the first and second walls along the door perimeter todefine a doorway, and wherein the door can be mounted to the door frameat the doorway with the hinge knuckles of the door and door framearranged in alternating fashion along a hinge axis, wherein at least aportion of the first and second walls of the door are fused togetheradjacent to the door perimeter and at least a portion of the first andsecond walls of the door frame are fused together adjacent to the doorperimeter, and wherein the first wall is separated from the second wallalong at least a portion of the door perimeter.
 2. The door panel ofclaim 1, wherein the first wall is separated from the second wall atleast along a free side of the door opposite its hinge side, and whereinwhen the door is separated from the door panel, the first wall isseparated from the door panel at the free side of the door farther fromthe hinge side of the door than where the second wall is separated atthe free side of the door to form an overlap at the door and door frameand the free side of the door.